feat(ui): simplify to 3-button manage layout and remove drawer grouping

test.js

@@ -47,6 +47,24 @@ assert.strictEqual(newItem.name, 'Test Yogurt');
 assert.strictEqual(newItem.quantity, 500);
 assert.strictEqual(newItem.unit, 'g');
 
+// Test Whole Packets: addPacket & removePacket
+console.log('Testing packet addition (+1 whole packet of 500g)...');
+const testPack = db.createItem({
+  name: 'Test Milk Pack',
+  quantity: 1000,
+  initial_quantity: 1000,
+  unit: 'ml'
+});
+const packAdded = db.addPacket(testPack.id, 1);
+assert.strictEqual(packAdded.quantity, 2000, 'Adding 1 packet should add 1000ml');
+
+console.log('Testing packet removal (-1 whole packet)...');
+const packRemoved = db.removePacket(testPack.id, 1);
+assert.strictEqual(packRemoved.quantity, 1000, 'Removing 1 packet should leave 1000ml');
+
+db.deleteItem(testPack.id);
+console.log('✓ Whole packet tests passed!');
+
 // Adjust grams: e.g. consumed 150g -> remaining 350g
 console.log('Testing partial consumption (-150g)...');
 const adjusted = db.adjustQuantity(newItem.id, { delta: -150 });